Don't know what your feeding them (besides the coffee grounds) but they are obviously enjoying their digs. Have you harvested any of the castings yet? Could you tell us a bit more about your bin......inside vs. outside, drainage/aeration methods, feeding rates etc. 'cause whatever your doing is obviously working very well .

Maybe you don't want or need another bin but with that many worms I'm sure you could remove some of the worms to get a second going. Or do what I did and convince one of your neighbours how much fun it is and just give some away.

Harry

It's nothing special. Just a tote inside a tote, kept spaced apart with small blocks, with 1/2" drain holes in the bottom in each corner and 10 to 12 vent holes along the top of both long sides of the inner tote.

Feeding could be anywhere from 4 times a week to nothing for two weeks or more. They seem to prefer coffee grounds, watermelon, old greens/salad, bread, and crumbs from the bottom of cereal boxes. I used to mist them with water when they were getting established, but haven't seen the need for that in a year. Sometime I moisten the new bedding, other times I don't.

I have it in a quiet corner of my kitchen where the top collects kids' backpacks and soccer cleats.

Well whatever you're doing, it's working. For me, I've seen how much they love any kinds of melon waste but I can't say as I've ever noticed them really going crazy over coffee grounds alone as yours seem to be doing. I've used crumbs from cereal boxes too. Give oatmeal(raw or cooked) a try sometime - they always enjoy that too.

What are you using for bedding? Lately I've been using a mix of egg-carton flats and hand-shredded newspaper. I don't soak it and wring it out though 'cause I find it just gets to "clumpy" so I just give it a good misting with water. That seems to allow for fluffier newspaper.

Harry

Oats, strawberries/hulls, banana peels as-is, apple skins and cores, paper flour bags, bread...No citrus, no pineapple. Nothing chopped up/frozen/prepped.

Bedding is torn newspaper, crumpled, soaked, water squeezed out, and fluffed up.

If you click on the image and enlarge it, you can see the small, white baby worms.

Good question. It certainly isn't lacking moisture, though any citrus would have been bare minimal, at most. Looks like a pH check is needed.